JPH0448893B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a construction method for an underground continuous wall used as an earth retaining wall or the like.

BACKGROUND TECHNOLOGY Conventionally, as methods for constructing an underground continuous wall, two methods are known: a method in which columns are formed one by one, and a method in which a plurality of columns are formed one after the other.

To explain the former construction method, first, a consolidation agent is spouted out while rotating an excavation shaft with stirring blades, and this consolidation agent is stirred and mixed with earth and sand to form a column. Bury stress material made of H-shaped steel. Next, a column is formed in the same manner as above so that it partially overlaps with the existing column, and the same stress material as above is embedded in this column. Thereafter, by repeating the same operations as above, an underground continuous wall can be constructed. Note that the stress material may be buried for each column depending on the required strength, or it may be buried for each desired number of columns.

To explain the latter construction method, this construction method uses a multi-axis excavator, for example,
Three excavation shafts with stirring blades are rotated to eject the solidifying agent, and the solidifying agent is stirred and mixed with the earth and sand to form pillars that partially overlap each other, forming the desired pillar. Bury stressed materials. Hereinafter, the operation is performed continuously to create an underground continuous wall, or the above operation is performed at desired intervals, and then the above operation is performed to fill in the spaces between the existing multiple consecutive pillars. Continuous walls can be created.

Problems to be Solved by the Invention However, among the above-mentioned conventional methods, the construction method in which columns are formed one by one is inferior in work efficiency, and since one excavation shaft rotates only in one direction, it is difficult to excavate. The balance during excavation is poor, the core is easily misaligned during excavation, and it is difficult to create a straight underground continuous wall. In addition, adjacent columns need to be overlapped with each other while avoiding stressed materials, and because the amount of overlap is small and the wall thickness of the overlapping part of the underground continuous wall is thin, a reliable water supply effect cannot be obtained. A situation may arise.
Furthermore, since a stress material made of H-shaped steel is used alone, it is necessary to use a thick and large material in order to obtain the required strength, which is not only expensive, but also reduces the thickness of the underground wall. Thickness increases.

On the other hand, the construction method of forming multiple columns at a time has the advantage of improving work efficiency, but since an odd number of excavation shafts are used, the number of excavation shafts with different rotation directions is different. The balance during excavation is poor, and the core is easily misaligned during excavation.
It is difficult to construct a straight underground continuous wall. In addition, since the stirring blades on each excavation shaft need to avoid adjacent excavation axes, the amount of overlap between columns formed at once is small, and the amount of overlap of subsequent columns with respect to the existing column is small. In order to avoid stressed materials, the thickness of the overlapping part of the diaphragm wall is narrow, so a reliable water-stopping effect may not be obtained. Furthermore, as in the conventional example above, since a stress material made of H-shaped steel is used alone, it is necessary to use a large material in order to obtain the specified strength, which is not only expensive, but also requires continuous underground construction. The wall becomes thicker.

The present invention solves the problems of the prior art as described above, and not only improves work efficiency, but also improves the balance during excavation and creates a straight underground continuous wall. In addition, by increasing the amount of overlap between the pillars, it is possible to create a continuous underground wall with an almost uniform thickness throughout, and it is possible to obtain a reliable water-stopping effect. Provides a method for constructing a medium continuous wall, and also improves the strength of stress materials, as well as improving stress and obtaining a specified strength by using small and thin stress materials, thereby reducing costs. It is an object of the present invention to provide a construction method for an underground continuous wall that can reduce the wall thickness of the underground continuous wall.

Means for Solving the Problems The technical means of the present invention for solving the above problems is to jet out a solidifying agent while rotating an even number of excavation shafts having stirring blades in opposite directions. Stir the binder with earth and sand to form columns adjacent to each other, repeat this operation to install adjacent columns in a row, and then repeat the above operation approximately equally between each two adjacent columns. These steps are performed sequentially to form overlapping columns so that the columns are continuous, and at the same time, the stress material is buried in the desired column.

Further, the above-mentioned stress material is configured in a unit shape consisting of a plurality of stress material bodies and a connecting plate connecting these stress material bodies, and this unit-shaped stress material is formed into each set of overlapping column bodies. It was designed to be buried astride.

The central portions in the longitudinal direction of the opposing elongated plates of the stressed material main body are connected by an elongated plate in a perpendicular direction, and the continuous plate has a length in the perpendicular direction to the opposing elongated plates of the stressed material main body. It is preferable to connect the connecting portions with the shaku plates so as to intersect diagonally, and to bury the connecting plates so that the intersecting portions of the connecting plates are located approximately at the center of the line connecting the central axes of the overlapping columns. Also,
It is preferable that the connecting plate connects the stress material bodies at a plurality of locations in the longitudinal direction.

Effect The effects of the above technical means are as follows.

Since the solidifying agent is ejected while rotating an even number of drilling shafts with stirring blades in opposite directions,
Balance during excavation can be improved.
Moreover, after arranging the adjacent columns, overlapping columns are formed in the same manner as above to almost evenly straddle between each two adjacent columns, and the columns are continuous. , Since the overlapping columns do not overlap each other, there is no risk of being affected by buried stressed materials, and by increasing the amount of overlap between the columns and thickening the wall thickness at the overlapped part, the entire wall has an almost uniform thickness. It is possible to construct underground continuous walls.

In addition, the strength of stressed materials can be improved by connecting multiple stressed material bodies with connecting plates and using them as a unit. It is possible to use something smaller and thinner than wood.

Example Hereinafter, the present example will be described with reference to the drawings.

First, the construction equipment used in the construction method of the present invention will be explained. Fig. 1A is a schematic side view of the creation device, Fig. 1B is a schematic front view of the main parts thereof, Fig. 2A is an enlarged view of the main parts of Fig. 1B, Fig. 2B is a bottom view thereof,
FIG. 2C is a sectional view taken along the line c-c of FIG. 2A.

As shown in FIGS. 1A and B and FIGS. 2 A to C, a rotating body 2 is mounted on a traveling body 1 so as to be able to turn. A vertical leader 3 is attached to the front side of the revolving structure 2, and the leader 3 is supported by a backstay 4. A guide 5 is provided along the vertical direction on the front side of the leader 3. A drive device 6 is supported by the guide 5 so as to be movable up and down, and the drive device 6 is suspended by a wire 7. A multi-axis device 8 linked to the drive device 6 is supported on the lower side of the drive device 6 so as to be movable up and down on the guide 5, and the multi-axis device 8 has an even number (two in the illustrated example) of hollow excavation shafts. 9 are suspended and supported in parallel so that they can rotate in opposite directions, and the lower end of each excavation shaft 9 has a spout 1 for discharging a solidifying agent, etc.
0 is formed. Spiral moving blades 11 and plate-shaped stirring blades 12 are attached alternately in the vertical direction to each excavation shaft 9 in order to excavate and stir the ground. That is, adjacent spiral moving blades 11 rotate in opposite directions, adjacent stirring blades 12 incline in opposite directions, and adjacent spiral moving blades 11 alternately change the number of turns, that is, the length. Adjacent stirring blades 12 are attached so as to be slightly offset from each other in the vertical direction. An auger head 13 is attached to the tip of each excavation shaft 9. Adjacent movable blades 11, stirring blades 12, and auger heads 13 are set so that the rotational trajectories of their outer edges do not overlap in a plane and are slightly separated from each other. Adjacent excavation shafts 9 are connected to each other by connecting members 14 at multiple locations in the vertical direction.
The excavation shafts 9 are rotatably inserted into the bearing portion 15 of the excavation shaft 9 so that the distance between the excavation shafts 9 is kept constant. The bearing portion 15 is connected by a plate-like portion 16 so as not to become an obstacle when excavating the ground as described later. A plate-like protruding portion 17 is formed on the outside of the bearing portion 15 to be as long as possible so as to fit within the rotation locus of the outer edge of the auger head 13, etc.
As described below, it is used to prevent twisting when excavating the ground. A steadying device 18 is provided at the bottom end of the reader 3.
is attached, and each excavation shaft 9 is supported by this steadying device 18 so as to be rotatable and movable up and down.

Next, the stress material (core material) will be explained.

3 and 4 show an example of the stress material, with FIG. 3 being a perspective view and FIG. 4 being an enlarged plan view. Third
As shown in the figures and FIG.
0 and a connecting plate 21 that connects these stress material bodies 20 into a unit shape. The stress material main body 20 has an I-shape or an H-shape in which the longitudinal center portions of the opposing elongated plates 22 are connected by a perpendicular elongate plate 23. Long plate 2 in the direction perpendicular to
Connecting plate 2 at multiple locations in the longitudinal direction between the connecting parts with 3
1, they are connected by welding so as to intersect in a diagonal direction. This connecting plate 21 may be welded to the stress material main body 20 in advance and transported to the construction site, or may be welded at the construction site.

FIG. 5 is an enlarged plan view showing another example of the stress material. In this example, the bent portion 21a at the end of each connecting plate 21 is connected by a bolt 24 and a nut 25 at a connecting portion of the long plate 23 closer to the long plate 22, and the other configurations are as described above. This is similar to the example.

Note that the stress member 19 shown in FIG. 3, FIG. 4, or FIG. , or connect two connecting plates to long plate 2
Various design changes can be made, such as connecting them in parallel between 2 and 23.

Next, a method for manufacturing an underground continuous wall according to the present invention using the above-mentioned construction apparatus and stress material 19 will be explained.

FIGS. 6A to 6C are explanatory plan views showing a construction method for an underground continuous wall in the first embodiment of the present invention.

In FIGS. 1 and 2, while operating the drive device 6 and moving the blade 1 downward along the guide 5, the multi-axis device 8 drives two excavation shafts 9, the movable blade 1, and the like.
1. The stirring blades 12 and auger head 13 are rotated in opposite directions to excavate the ground. At this time,
In hard ground, excavation can be easily performed by spouting bentonite or the like from the spout 10 of the excavation shaft 9. As the excavation is carried out, the excavated earth and sand are moved upward by the spiral moving blades 11, and here, the excavated earth and sand can be uniformly stirred by the stirring blades 12. During this excavation, 2
Since the book excavation shaft 9, movable blade 11, stirring blade 12 and auger head 13 are rotated in opposite directions, balance can be improved and misalignment can be prevented. When excavating to a predetermined depth, the excavation shaft 9
Consolidating agent instead of bentonite or the like is spouted from the spout 10, and the excavation shaft 9 is pulled up while rotating and moving up and down. During this time, the excavated earth and sand are moved upward together with the consolidation agent by the spiral moving blades 11.
The mixture is stirred and mixed by the stirring blade 12. In this way, as shown in FIG. 6A, two columns 26a and 27a are formed adjacent to each other, in which the solidifying agent is stirred and mixed with the excavated soil. Next, the above operation is repeated at predetermined intervals to form two columns 26a and 27a. When the first forming operations ₁ , ₂ , ₃ , etc. of the columns 26a, 27a are completed in this way, FIG. 6B
As shown in FIG. 1, the _second process of forming columns 26b, 27b is carried out in the same manner as above to fill the gap between the first existing columns 26a, _27a .
_3. Do... In this way, adjacent columns 26
a, 27a, 26b, 27b, . . . are arranged in a row. Next, as shown in FIG.
c, 27c is formed, and after forming, the column body 26 for duplication is formed.
The stress material 19 shown in FIGS. 3 and 4 is buried in the holes c and 27c. At this time, the column 26 for duplication
The stress material main body 20 is buried in the central part of the connecting plates 26c and 27c, and the connecting plate 21 is placed so that the intersecting part of the central part thereof is located approximately in the central part on the line connecting the central axes of the overlapping columns 26c and 27c. Bury it. Moreover, in the central part on the line connecting the central axes of the overlapping columns 26c and 27c, the spacing between the columns 26c and 27c is the narrowest, and since they are almost close to each other, they tend to collapse during excavation and are easily buried. be able to. The formation of the overlapping columns 26c, 27c and the embedding of the stress material 19 are performed sequentially at predetermined intervals like ₁ , ₂ , ₃ , etc. in the same way as above, and then the existing overlapping columns 26c, 27c are The spaces between the columns 26c and 27c are filled with ₁ , ₂ , . . . . Therefore, it is possible to increase the amount of overlap by overlapping the columns 26 and 27 almost up to the vicinity of the central axis, and increase the thickness of this overlapping part, thereby creating an underground continuous wall with approximately the same thickness. , the water-stopping effect can be improved. As described above, by using the unit-shaped stress material 19 in which the stress material main bodies 20 are connected by the connecting plate 21, it is less susceptible to the influence of earth pressure etc. during the formation of adjacent columns, and a stable buried state can be maintained. be able to. It also has excellent strength, so in order to obtain a certain level of strength, it is possible to use thinner materials compared to conventional examples, or it is possible to reduce the size of the diaphragm wall by making it thinner. can be formed.

Next, a second embodiment of the construction method of the present invention will be described.

FIG. 7 is an explanatory plan view showing a second embodiment of the construction method of the present invention.

In this embodiment, the overlapping columns 26c, 2
Every other column in 7c, that is, each column 26c
As in the conventional example, a stress material 28 made of a single piece of I-type steel (or H-type steel) is embedded in the structure, and other aspects are the same as in the first embodiment.

Next, a third embodiment of the construction method of the present invention will be described.

FIG. 8 is an explanatory plan view showing a third embodiment of the construction method of the present invention.

In this embodiment, 26c, 27c for duplication
As in the conventional example, stress members 28 made of a single I-type steel (or H-type steel) are buried in every other one, and the rest is the same as the first embodiment. .

In addition, in the creation apparatus used in the above example, a case was explained in which a spiral moving blade 11 and a plate-shaped stirring blade 12 were used in combination as stirring blades, but the invention is not limited to this. Depending on the target ground, only the spiral moving blades 11 may be continuously provided, or only the plate-shaped stirring blades 12 may be provided. Further, in the above embodiment, the case where two pillars 26 and 27 are formed each is explained, but an even number of pillars 26 and 27 may be formed. In other words, the excavation shafts 9 having mutually different rotation directions It is sufficient to provide them symmetrically on both sides to improve balance during excavation, etc. At this time, Figure 3,
When using the stress material 19 shown in FIG. 4, the number of stress material bodies 20 may be increased in accordance with the number of stress materials 19 and the stress material bodies 20 may be connected by a connection plate 21. Further, in the above embodiment, two pillars 26 and 27 are formed at predetermined intervals, and then the pillars are formed to fill in the spaces between the existing pillars, and the two pillars that are being formed are However, in both the work of arranging adjacent columns and the work of forming overlapping columns, the columns in this work are not overlapped, so the above order is applied. The formation order is not limited to, and various formation orders can be selected, such as sequentially.

Effects of the Invention As described above, according to the present invention, since an even number of columns are formed, work efficiency can be improved. Further, since the solidifying agent is jetted out while rotating an even number of excavation shafts having stirring blades in mutually opposite directions, the balance during excavation can be improved. Moreover, after arranging the adjacent columns, overlapping columns are formed in the same manner as above to almost evenly straddle between each two adjacent columns, and the columns are continuous. , Since the columns for duplication do not overlap each other, there is no risk of being affected by buried stressed materials, and the amount of overlap between the columns is increased.
By increasing the thickness of the overlapping part, it is possible to create an underground continuous wall with a substantially uniform thickness throughout, and a reliable water-stopping effect can be obtained.

In addition, the strength of stressed materials can be improved by connecting multiple stressed material bodies with connecting plates and using them as a unit. It is possible to use a smaller size and thinner wall compared to other materials, and therefore it is possible to reduce costs and reduce the thickness of the underground continuous wall.

[Brief explanation of the drawing]

Figures 1A and B and Figures 2 A to C show the construction equipment used in the construction method of the present invention, Figure 1A is a schematic side view of the construction equipment, Figure 1B is a schematic front view of the main parts, Figure 2A is an enlarged view of the main part of Figure 1B,
Figure B is the bottom view, Figure 2 C is the c- of Figure 2 A.
A sectional view taken in the direction of arrow c, FIGS. 3B and 4 show examples of stress materials used in the construction method of the present invention, FIG. 3 is a perspective view, FIG. 4 is an enlarged plan view, and FIG. FIGS. 6A to 6C are explanatory plan views showing another example of the stress material used in the construction method of the underground continuous wall in the first embodiment of the present invention. 8 and 8 are the second and third embodiments of the present invention, respectively.
It is an explanatory plan view showing the construction method of the underground continuous wall in the 3rd example. 9... Excavation shaft, 11... Moving blade, 12... Stirring blade, 13... Auger head, 14... Connection member,
19... Stressed material, 20... Stressed material main body, 21...
Connecting plate, 26, 27... Column body, 28... Stressed material.

Claims (1)

[Claims] 1 An even number of excavation shafts each having stirring blades are rotated in opposite directions to eject a solidifying agent, and the solidifying agent is stirred and mixed with earth and sand to form adjacent columns. This operation is repeated to arrange adjacent columns in a row, and the above operation is sequentially performed to almost evenly straddle each two adjacent columns to form an overlapping column. A construction method for an underground continuous wall, which is characterized by making the wall continuous and burying stress material in a desired column. 2. The stressed material is constructed in the form of a unit consisting of a plurality of stressed material bodies and a connecting plate connecting these stressed material bodies, and this unit-shaped stressed material is straddled over each set of overlapping columns. 2. The method for constructing an underground continuous wall according to claim 1, wherein the underground continuous wall is buried. 3. The construction method for an underground continuous wall according to claim 2, wherein the longitudinal center portions of the long plates facing each other with the stressed material bodies are connected by a long plate in a perpendicular direction. 4. The connecting plate connects the connecting parts of the opposing elongated plates and the orthogonal elongated plates in the stress material main body so as to intersect in the diagonal direction, and the intersecting part of the connecting plates is approximately at the center of the overlapping column. 4. The method for constructing an underground continuous wall according to claim 2 or 3, wherein the underground wall is buried so as to be located in the center on a line connecting the axes. 5. The construction method for an underground continuous wall according to any one of claims 2 to 4, wherein the connecting plate connects the stress material bodies at a plurality of locations in the longitudinal direction.